Home > About Us > Mapping Ultrasound Scan

Why do I need a Mapping Scan?

Prior to undertaking any ultrasound guided treatments a mapping is performed. The Mapping Scan is to identify the exact position and severity of the underlying vein problem. This information helps determine which is the most appropriate of the available ultrasound guided treatments for a particular patient.

How is the scan done?

Ultrasound gel is applied to your skin and a plastic probe (called a transducer) is placed on the gel. The ultrasound itself cannot be felt but the examiner may squeeze parts of your leg to augment blood flow through the venous system.

Demonstration of Mapping Scan

What is Ultrasound?

As ultrasound uses sound waves to create images of the inside of the body. Ultrasound is in essence sound whose frequency is above the range of human hearing. Sound is categorised according to its frequency (number of mechanical variations occurring per unit time). Human audible range 20-20,000Hz, Diagnostic Ultrasound 1-20mHz.

Ultrasound can be used to evaluate internal organs because when sound waves are transmitted into the body they are reflected and scattered and the sound echoes that bounce to the surface can be collected and used to form an image of the structure below the skins surface.

What is B Mode?

The images used in diagnostic ultrasound are produced with B-Mode (or brightness mode) techniques. This is essentially a pattern of dots that appear on the monitor as a result of the signals collected by returning ultrasound echoes being processed by the ultrasound system. The brightness of each dot is in proportion to the strength of the echo received.

What is Doppler?

The Doppler effect refers to the change in the frequency of the ultrasound waves as a result of movement. It is named Doppler after the Austrian physicist (Christian Doppler) who first described the effect in the 19th century.

What is Colour Doppler Imaging?

Colour Doppler imaging is when an area of the B-Mode field of view is assessed for evidence of Doppler shifts. When shifts are detected these are coloured coded red or blue as flow towards or away from the ultrasound. The colour display is superimposed on the B-Mode image on the monitor. By convention ultrasound echoes moving towards the ultrasound transducer are seen as shades of red and those representing flow away are seen as shades of blue.

Detecting reverse flow or reflux is very important in assessing the degree of underlying venous disease.

What is Duplex Doppler Ultrasound?

A Duplex Ultrasound is a form of image display which can simultaneously show both spectral (i.e. spectrum of blood flow velocities) and colour flow images.

The Duplex Ultrasound provides accurate anatomical location of the blood flow under investigation.

Overall a Duplex Ultrasound provides:

• Visualisation of anatomy (B-Mode)
• Flow velocities (Spectral Doppler)
• Direction of flow (Colour Flow)

What make of Duplex Ultrasound is used?

At the Melbourne Leg Vein Centre we use the Terason Ultrasound system. Terason is made by Teratech Corporation in the USA. Teratech is a market leader in the use of ultrasound in the field of ultrasound guided vein treatments.

LINK: http://www.terason.com/products/t3000.asp